The present invention relates to male terminal fittings and, more particularly, a male terminal fitting having a contact protrusion and a method of manufacturing the same.
Various attempts have heretofore been undertaken to develop a male terminal fitting of the type having a plate-shaped contact protrusion as disclosed in FIGS. 1 and 2. In such a male terminal fitting, the plate-shaped contact segment 1 is fabricated first by stamping a conductive thin metal sheet in a developed stage and subsequently bending the thin metal sheet into a final product. In particular, the plate-shaped contact protrusion 1 is comprised of an elongated base plate component 2, and an overlapping fold plate component laterally extending from one end of the base plate component and folded to lie over the base plate component 2. A distal end 3a of the overlapping fold plate component 3 is further folded toward the base plate component 2 such that a tabular portion 4 is formed. The presence of the hollow portion 4 enables the plate-shaped contact protrusion 1 to have a desired thickness L1 even when using the thin sheet material.
However, since the tabular portion 4 is internally formed when forming the overlapping fold plate component 3 toward the base plate component 2, central portions of the base plate component 2 and the overlapping fold plate component 3 are caused to be collapsed in depths L2, L3, respectively, due to external press forces exerted thereto during the forming operation as shown in FIG. 2.
With such deformations, the base plate component 2 and the overlapping fold plate component 3 do not have desired flatness, resulting in a decrease in contact surface areas against mating walls of an associated female terminal fitting with a degraded reliability in electrical contact.
To address such an issue, another attempt has been proposed to develop a male terminal fitting whose plate-shaped contact protrusion is shown in FIGS. 3 and 4, wherein a base plate component has a longitudinal extension 7 which is folded back to form an overlapped structure on which overlapping plate components 6, 6 are folded inward to lie on the overlapped structure as disclosed in Japanese Patent Provisional Publication NO. 10-3956. With such a structure, even when the plate-shape contact protrusion is exerted with the external press forces, the presence of the overlapped structure 7, which is laminated with the overlapping plate components 6, 6, avoids the central portions of the base plate component 2 and the overlapping plate components 6, 6 from being collapsed.
However, with a particular structure proposed in such a Japanese Provisional Publication, the presence of the longitudinal extension 7, which longitudinally extends from the distal end of the base plate component, needs an elongated sheet material with a remarkably increased width, causing an increase in a material cost and an increase in waste material.
Further, the presence of a bending step for bending the longitudinal extension 7 such that it is folded back to the base plate component 5 is reflected in an increase in the number of bending formation steps, thereby increasing the manufacturing cost of the male terminal fitting.
The present invention has been made with a view to addressing the above issues and has an object to provide a male terminal fitting and a method of manufacturing the same which is reliable in ensuring a flatness in a base plate component and an overlapping fold plate component while enabling the male terminal fitting to be manufactured at a low material cost and a low manufacturing cost.
To achieve the above object, according to a first aspect of the present invention, there is provided a male terminal fitting comprising: a plate-shape contact protrusion formed at one side of said male terminal fitting for mating with a female terminal fitting; and a conductor clamping portion located at the other side of said male terminal fitting to allow a conductor of an electric wire to be clamped; wherein said plate-shaped contact protrusion includes a base plate component longitudinally extending from said conductor clamping portion in an elongated plate shape, an overlapping fold plate component laterally extending from one side of said base plate component and folded to overlap with said base plate component, and a flatness securing plate component overlapping with said base plate component and said overlapping fold plate component to enhance flatness conditions of said base plate component and said overlapping fold plate component, respectively.
According to a second aspect of the present invention, there is provided a male terminal fitting comprising: a plate-shape contact protrusion formed at one side of said male terminal fitting for mating with a female terminal fitting; and a conductor clamping portion located at the other side of said male terminal fitting for clamping a conductor of an electric wire; wherein said plate-shaped contact protrusion includes a base plate component longitudinally extending from said conductor clamping portion in an elongated plate shape, a first overlapping fold plate component laterally extending from one side of said base plate component and folded in one direction toward the other end of said base plate component to overlap with said base plate component, and a second overlapping fold plate component which extends from said first overlapping fold plate component at a position close to the other end of said base plate component and which is folded back in another direction opposed to said one direction to overlap with said first overlapping fold plate component; and wherein said first overlapping fold plate component serves as a flatness securing plate component to ensure flatness conditions of said base plate component and said second overlapping fold plate component, respectively.
According to a third aspect of the present invention, there is provided a male terminal fitting comprising: a plate-shaped contact protrusion formed at one side of said male terminal fitting for mating with a female terminal fitting; and a conductor clamping portion located at the other side of said male terminal fitting for clamping a conductor of an electric wire; wherein said plate-shape contact protrusion includes a base plate component longitudinally extending from said conduct clamping portion in an elongated plate shape, a first overlapping fold plate component laterally extending from one side of said base plate component and folded in one direction toward the other end of said base plate component to overlap with said base plate component, and a second overlapping fold plate component which extends from the other end of said base plate component and which is folded back in another direction opposed to said one direction to overlap with said base plate component; and wherein said base plate component serves as a flatness securing plate component to ensure flatness conditions of said first and second overlapping fold plate components, respectively.
In other words, according to a fourth aspect of the present invention, there is provided a male terminal fitting comprising: plate-shaped contact means formed at one side of said male terminal fitting for mating with a female terminal fitting; and conductor clamping means located at the other side of said male terminal fitting for clamping a conductor of an electric wire; wherein said plate-shaped contact means includes base means longitudinally extending from said conduct clamping means in an elongated plate shape, overlapping fold means laterally extending from one side of said base means and folded to overlap with said base means, and flatness securing means overlapping with said base means and said overlapping fold means to enhance flatness conditions of said base means and said overlapping fold means, respectively.
According to a fifth aspect of the present invention, there is provided a male terminal fitting comprising: plate-shaped contact means formed at one side of said male terminal fitting for mating with a female terminal fitting; and conductor clamping means located at the other side of said male terminal fitting for clamping a conductor of an electric wire; wherein said plate-shaped contact means includes base means longitudinally extending from said conductor clamping means in an elongated plate shape, first overlapping fold means laterally extending from one side of said base means and folded in one direction toward the other end of said base means to overlap with said base means, and second overlapping fold means which extends from said first overlapping fold means at a position close to the other end of said base means and which is folded back in another direction opposed to said one direction to overlap with said first overlapping fold means; and wherein said first overlapping fold means serves as flatness securing means to ensure flatness conditions of said base means and said second overlapping fold means, respectively.
According to a sixth aspect of the present invention, there is provided a male terminal fitting comprising: plate-shaped contact means formed at one side of said male terminal fitting for mating with a female terminal fitting; and conductor clamping means located at the other side of said male terminal fitting for clamping a conductor of an electric wire; wherein said plate-shaped contact means includes base means longitudinally extending from said conductor clamping means in an elongated plate shape, first overlapping fold means laterally extending from one side of said base means and folded in one direction toward the other end of said base means to overlap with said base means, and second overlapping fold means which extends from the other end of said base means and which is folded back in another direction opposed to said one direction to overlap with said base means; and wherein said base means serves as flatness securing means to ensure flatness conditions of said first and second overlapping fold means, respectively.
On the other hand, a first male terminal fitting manufacturing method of the present invention comprises: preparing a blank sheet of elongated conductive metal sheet; stamping said elongated conductive metal sheet to form a plurality of sequentially arrayed terminal fittings, in developed states, which are integrally connected to a carrier, each of said terminal fittings including a conductor clamping portion extending from said carrier, a clamping body connected to said conductor clamping portion, and a plate-shaped contact protrusion which is composed of a base plate component longitudinally extending from said conductor clamping portion via said clamping body, a flatness securing plate component laterally extending from one side of said base plate component, and a overlapping fold plate component laterally extending from the other side of said base plate; and
forming said conductor clamping portion, said clamping body band said plate-shaped contact protrusion into respective final shapes; wherein, after said forming step, said flatness securing plate overlaps with said overlapping fold plate component to ensure flatness conditions of said base plate component and said overlapping plate component, respectively.
A second male terminal fitting manufacturing method of the present invention comprises: preparing a blank sheet of elongated conductive metal sheet; stamping said elongated conductive metal sheet to form a plurality of sequentially arrayed terminal fittings, in developed states, which are integrally connected to a carrier, each of said terminal fittings including a conductor clamping portion extending from said carrier, a clamping body connected to said conductor clamping portion, and a plate-shaped contact protrusion which is composed of a base plate component longitudinally extending from said conductor clamping portion via said clamping body, a first overlapping plate component laterally extending from one side of said base plate component, and a second overlapping fold plate component laterally extending from the other side of said base plate; and
forming said connecting segment, said clamping body and said plate-shaped contact protrusion into respective final shapes; wherein, after said forming step, said base plate component overlaps with said first and second overlapping fold plate components and serves as a flatness securing plate component to ensure flatness conditions of said first and second overlapping fold plate components, respectively.
A third male terminal fitting manufacturing method of the present invention comprises: preparing a blank sheet of elongated conductive metal sheet; stamping said elongated conductive metal sheet to form a plurality of sequentially arrayed terminal fittings, in developed states, which are integrally connected to a carrier, each of said terminal fittings including a conductor clamping portion extending from said carrier, a clamping body connected to said conductor clamping portion, and a plate-shaped contact protrusion which is composed of a base plate component longitudinally extending from said conductor clamping portion via said clamping body, a flatness securing plate component laterally extending from one side of said base plate component, and an overlapping folding plate component laterally extending from the other side of said base plate; and forming said conductor clamping portion, said clamping body band said plate-shaped contact protrusion into respective final shapes; wherein, after said forming step, said flatness securing plate component overlaps with said base plate component and said overlapping fold component to ensure flatness conditions of said base plate component and said overlapping fold plate component, respectively.